When you need to cut off a rusted exhaust pipe, grind down a welded seam, or clean scaling rust from a frame, an angle grinder is the tool to grab. It spins a circular disc at speeds up to 11,000 RPM. You can swap discs for different jobs: thin cutoff wheels for slicing metal, thick grinding wheels for smoothing welds, or wire wheels for removing rust. Always use the protective guard and hold the tool with both hands. The sparks can travel far, so clear the area of flammable materials.
Mechanic Glossary
Angle Grinder
A handheld electric or pneumatic rotary power tool used with abrasive wheels for cutting, grinding, and smoothing metal parts.
Frequently Asked Questions
A 4.5-inch angle grinder is the standard shop size. It is small enough to fit in tight spaces but large enough to cut thick metal.
Never remove the guard. A cutting disc spinning at high speed can shatter and cause severe injuries if the guard is not in place.
Cutoff discs are thin (about 1/16 inch) and designed only for slicing metal. Grinding discs are thick (1/4 inch) and made to handle side pressure for smoothing.
If you pinch the cutting disc in the metal slot, the tool will jump back violently. Keep the cut straight and don't force the tool.